What is the purpose of a blow-off valve in a boiler?

The purpose of a blow-off valve in a boiler is primarily to release waste water and sludge from the boiler. Over time, impurities and residual sediment can accumulate in the boiler water, which can negatively impact performance and efficiency. The blow-off valve provides a means for the operator to regularly purge these contaminants, thus maintaining the quality of the water in the system.

By discharging these byproducts, the blow-off valve helps prevent scaling and corrosion inside the boiler, extending the equipment's lifespan and ensuring safe operations. It is a critical component in the maintenance routine for any steam or hot water boiler system, as proper blow-off procedures contribute to efficient and safe boiler operation.

In contrast, the other options serve different purposes related to boiler operation and maintenance but do not reflect the specific role of the blow-off valve as accurately as the correct answer does.